Ok question!

So I have a question I had an anatomy test and had to come back to finish measurements of baby I went to second one and baby measured 1 pound 1 ounce I'm 22w6days today and they told me baby is healthy and fine congrats and go enjoy now I get a phone call for another anatomy test April 18th am I suppose to get them every now and then to check growth of baby or something they had me worried I'm assuming if it was serious they would call me in right away has this happened to anyone?